... polyacrylamide, for instance, is a strong carcinogen. In contrast, the third group of flocculants is biodegradable and safe but has flocculating activities too weak for industrial use. Therefore, screening ... (1980) A simplified ultrasensitive silver stain for detecting proteins in polyacrylamide gels. Anal. Biochem., Vol.105, No.1, 361-363. Ough, L. D., in Methods in Carbohydrate Chemistry (Whistler, ... examined flocculating properties in an effort to develop an effective extraction method for bioflocculants from the microbial cell surface. Materials and Methods Activated sludge samples....